Nonyl phthalates



Patented Sept. 9, 1952 I John T. Rutherford, Berkeley, Calif., assignor to California Research Corporation, San Franv A cisco, Calif., a corporation of Delaware NoDrawi ng. Application April 9, 1949,

Serial No. 86,601

2 Claims. (ma-.475)

This invention relates to novel alcohols .hav- *inga formula of the type i RTC 'O wherein R is an alkyl'radical containing 8 carbon atoms and-possessing a chainstructure corresponding to that foundv in copolymers of nbutene-l and n-butene-Z, and to the process of preparing them. This invention also relates to novel and valuable plasticizer derivatives obtained from alcohols. Higher alcohols are widely used today in the preparation of. valuable ester plasticizing agents.

(production of synthetic alcohols has been the application of the OX reaction' to olefinic hydrocarbons. The 'OXO reaction is that in which an olefinic hydrocarbon is carbonylated and hydrogenated by the addition of carbon monoxide and hydrogen to the olefin under proper temperature and pressure conditions. in the presence of a catalyst. Alcohols of practically any desired molecular weight and structure may be prepared by this-means. r a i The OX0 reaction first appeared in an article published in the Journal of the American Chemical Society of August 1930 by Smith, Hawk and "Golden. The authors were primarily interested in'studying the mechanism of the then new'Fischer-Tropsch synthesis of higher hydrocarbons from water gas and only noted that water-soluble, oxygen-containing compounds, such as alcohols 1 and ketones, were formed as intermediates in the reaction. Since that time,

the OX0 reaction has been used to prepare several different types of alcohols by various 1:4

not fully known to the art as yet. However,

for the purposes of this application, it may be considered merely asan addition of CO and H to the olefin so that the double bond becomes saturated anda CH2OH, group is attached to .one or theother of the-carbon atoms adjacent to form the alcohol. 1

stages.

2 to the double bond. During the reaction an aldehyde one carbon atom higher than the olefin is formed first. The aldehyde is then reduced by the hydrogen present to form the corresponding alcohol. A metal catalyst capable of forming a carbonyl structure, such as cobalt, nickel, and iron, is generally utilized in the reaction.

.The OX0 reaction may be performed in two A firststage wherein the olefin is oxonated to form the corresponding one carbon atom higher aldehyde, and a second stage in which the aldehyde is reduced byhydrogenation The ,OXO reaction may also proceed in a single stage fashion in which oxonation to aldehyde and hydrogenationto alcohol are allowed to occur at the same time, thus producingan alcohol from the olefin in one general reaction.

Although either the two stage orthe single stage reaction is suitable for the purposes of myinvention, since they'both yield the same general end product, it is the latter, single stage process, which has been utilized in making my invention.

The ideal hydrocarbonfor the production of synthetic alcohols should be one of which there is a plentiful supply. It may be obtained from any of the sources now known, such as, destructive hydrogenation of coal; Fischer-Tropsch synthesis applied' to water gas produced from coal for natural gas; petroleum refinery hydrocarbons and the like. Any other source by which unsaturated hydrocarbons of the desired type may be economically produced would also be satisfactoryfor the purpose of my invention. Further, it has been'determined that the alcohol produced should contain at least eight car- ,bon atoms in order that the plasticizer derivative be not excessively volatile. Low volatility efficiency of the ester in plastic compositions is greatest for alcohols having from sevento thirteen "carbon atoms, and especially those containing from eightfto ten carbon atoms. Generally speaking, though, hardness and flexibility efiiciency characteristics of the various plasticizers are empirical in nature and incapable of prediction. Consequently, considerable research mustbe performed to find alcohols suitable for the production of, desirable ester plasticizing *teristics was made. generally to possess a boilingrange of about agents. It was with this knowledge of the problem of finding an alcohol both economical and superior in properties that the investigations leading to my invention were conducted.

I have discovered new and distinct nonyl alcohols having a formula of the type wherein R is an alkyl radical containing 8 carwherein R1 and R2 are alkyl radicals containing 8 carbon atoms and possessing a chain structure corresponding to that found in copolymers of 'n-butene-l and n-butene-2. These phthalates are distinct and superior plasticizing agents.

The first step in producing my novel nonyl alcohols is the preparation of copolymers of n-butene-l and n-butene-2. Both n-butene-l and n-butene-Z are available in good supply in modern petroleum refinery operation. The co.-

polymerization may be accomplished by any of the means already known to the art. The copolymer used in making this invention was prepared by polymerizing a synthetic gas mixture of pure hydrocarbons containing substantial proportions of n-butene-l and n-butene-Z. This gas mixture should be-substantially free of isobutene. The polymerization reaction was carried out under pressure and at an elevated temperature in the presenceof a phosphoric acid catalyst. The product was then stabilized, filtered and fractionated to obtain an octene cut. Theproportions of n-butene-l and n-butene-2 suitable for the purposes of my invention may be any of those generally found in equilibrium mixtures of the two hydrocarbons. In the presence of an acid catalyst an isomerization reaction usually occurs in which an excess of n-butene-l over the equilibrium proportion for the particular reaction temperature is isomerized 'to form n-butene-2 and to reach the equilibrium for that temperature. portions for n-butene-l in a mixture of n-butene-l and n-butene-2 These equilibrium proin the presence of an acid catalyst generally range from about at room temperature of 25 C. to about 60% at a temperature of around 1200 C.- A more practical and common range of proportions of n-butene-l in equilibrium mixtures of n-butene-l and n-butene-2 would be from about 20% to=40%.'

5 Since it is the chain structure of this copolymer which undoubtedly contributes the novel and unexpected propertiesto my OX0 nonyl alcohol, a thorough analysis of'its physical charac- The copolymer was found 100 to 125 C., a bromine number of about 150,

and a refractive index of the order of 1.416.

The desired nonyl alcohol mixture is then 4 prepared from the above n-butene-l and nbutene-2 copolymer type of hydrocarbon by the addition of carbon monoxide and hydrogen thereto. In general, a pressure of from about 2,500 to about 5,000 pounds per square inch is maintained with the carbon monoxide and hydrogen present inthe form of a mixture in which the carbon monoxide represents from about 40% to 70% and the balance is hydrogen and inert gases. The reaction is conducted at a temperature of about 300 to 400 F., preferably 340 to 380 F. in the presence of a catalyst of the cobalt,

iron or nickel type. It is known that the reaction will proceed under other conditions and proportions, but thoseset forth are ordinarily used. After the reaction is completed, the catalyst is 'withdrawn from the mixture and sodium hydroxide added to convert any aldehydes formed to higher boiling materials. The caustic is then drawn off, the crude product water-washed and fractionated. to give the desired nonyl alcohol cut boiling between about and C. at 50 mm. pressure.

The novel phthalate derivative of the above OX0 nonyl alcohol is next prepared by reacting it with a phthalic acid reagent in the presence of a catalyst such as p-toluene sulfonic acid monohydrate. The phthalic. acid reagent may be any of the isomers of phthalic acid or its anhydride. Although my esterification was performed in-an atmosphere of carbon dioxide or nitrogen at a temperature of from about 300F. to 360 F., any other inert gas and reaction temperature within the knowledge of a person skilled in the art may be used.

The above di-nonyl-v phthalate was found to have unexpectedly desirable qualities: asv a plasticizing .agentwhen tested with a vinyl chloride polymer type of resin.' Itwas superior inpractically every-respect tested to phthalates derived from OX0 alcohols'produced using oth'erreadily' available'petrole'um refinery hydrocarbons.

In preparing these novel nonyl alcohols and their phthalate'derivatives; the following examples illustrate more ,explicitlythe type of procedure followed:

Preparation. of n-butene-I and. n-butene.-2. copolymer A synthetic liquefied gas mixture'was prepared having the following composition:

Per cent by weight Ethylene 0.2 Propylenes 0.2 n-Butane 56.9

iso-Butane 1.8 n-Butene-l 13.5 n-Butene-2 m 26.1

Butadiene 1.3

Total 100.0

4,530 ml. of the above liquefied gasmixturewas pumpedthrough a bed of catalyst composed of Fullers earth pellets saturated with 70% phosphoric acid. The liquid was fed at a rate of 2.6 liters per hour per liter of catalyst. A catalyst temperature of 250 C. and aipressure: of .250

pounds per square inchv were: maintained The product containing polymers and unreactedhydrocarbons' wasstabilized; filteredand fractionstill.

ally distilled to obtain an octan'egcut having the. following analysisr 1 l Bromine No 149 i Density"(/20) 0.728 gmsi'per ml.

Refractive index (ZO/D) 1.416 V -"EXAMPL E2 Preparation of nonyl; alcohol from'n-b utene -i and n-buterie-Z copolymer L 1 380 gms. of n-butene-l and mbutene-Zcopolymer prepared as in Example. 1,. above, .was charged to a stainless steel autoclave. with 80. gmsof catalyst comprising 5'7 gms. of water and 23 gms. of cobaltous acetate'tetrahydrate. The. autoclave was purged'twice and then pressured to 2,000 pounds persquare inch with carbon Q.

monoxide and hydrogen in a volume. ratio of 1-:.1-.'-" The mixture was agitated and heatedtoxa temperature of 380 to 400 F. where thereaction began. When the reaction commencedja pressure drop occurred due to gas/being takenup by the olefin. Beginning .at this point, carbon monoxide and hydrogen gas in the ratio .of 1:1 were added to maintain a pressure of from'3,000 to;

3,500 pounds per square inch until the reaction was completed as evidenced by no more. gas being taken up. The autoclave was then dumped and the crude alcohol weighed. j Asample run follows: Time of run 3 hrs. Density of crude 0.84 CO No. of crude 24.4

The crude alcohol was then washed in a stirred vessel with about 20 per cent by volume of water at atemperature of 200 F. for one hour to rev .butylene polymers are comparable to the copolymove the, cobalt catalyst. The water layer wasdrawn off and the crude next stirred with 25 per cent by volume of caustic (25 per cent NaQIjI) at 200 F. for two hours to condense any .alde-' dilute caustic followed. by hot water. toreniove 5 the catalyst. An ester cut was obained; by distillation of the crude ester at reduced pressure.

The ester cut obtained was then clay-treated .to reduce the neutralization derived has the. following analysis:

Viscosity at 210 F.,SSU 43.8 Viscosity index (Dean and Davis) 1 56 The over-all yield of the ester baseacn the phthalic anhydride charged wasabout 95 per cent of theory.

Inorder to illustrate the sepal pro erties of thefOXO nonyl alcohol of my inventionfandi the novel phthalate' plasticizing agent prepared the following procedure.

from it, a. series of tests were performed using: I

A proper evaluation of the phthalate plasticizr derivative of my novel alcohol requires. a comparisonzwith the phthalate derivatives of other alcohols of'thesarhe general class; For this comparison, a di-nonyl orthophthalate derived from nonyl alcohols producedby the OX0 reaction on di-isobutylene polymers was selected. Di-iso- Chemical 00., Cleveland, Ohio. This mixture was hydes present to higher boiling materials. The 3 caustic was then drawn off, thecrude water? washed and distilled to 'give an alcohol cut boil mg in the range of 120 to'130 C. at mm. presi sure. Such'a out has the followingcharacter istics. f I OHNO 11 u 385 CO No 15.9. Refractive indexlM 20/D) .1.4379 Density (2o 4 0.8407

The yield of alcohol was 54 per cent by volume of the crude reaction mixture "charged'to the EXAMPLES t Preparation of ii-nonyl phthalatev frown-bu.-

tene-l and n-butene-Z copolymer alcohol. 292 gms., or'two mols, of the above OXOj nonyl alcohol, and 1126 gms, or0 .85 in'ol, of

phthalic anhydride along with1.9gms., or 0.01 mol, of petoluene sulfonic as" catalyst were charged to a stirred vessel equippedwith anover head trap and thermometer Well. inert at: mosphere of carbon dioxide was maintained. After one-half hour of stirring, the mixture was heated and brought to reflux. The reactionwas complete in about one hours time as indicated from the calculated amount of water obtained in the overhead trap. The temperature rose from 304 F., when thewaterfirst began to come off, to. 362.Faat completion time. The crude ester product was next removed and washed with pressed between heated platens forjabout five minutes to form a clear homogeneous test sheet.

The volatility of each plasticizer was measured by cutting duplicate strips from each pressed sheet, one inch 'by three inches in size. They were marked, weighed and placed in an oven. at

C. for two consecutive twenty-four hour periods. The loss in weight sustained during each period was taken as a loss of plasticizer and is expressed in percentage loss of total starting.

plasticizer, in the tablefollowing.

The hardness characteristics for each ofthe plasticizing agents were determined by means of a Box Model-A hardness tester at a temperature of 75 Fh-as described in A.. S., T. M. method D676-44T. The sample on which the test was performed was made from the pressed plastic sheets described above and had a thicknes of about 0.16 inch; The measurementsiof the test a were obtained in Shore hardness unitsfas set I out in the table below.

The flexibility characteristics were determined by the method of described in their article in Industrialand Engineering Chemistry, vol. 34 (1942),.ipages 1218-22. a

In this test, the temperature is. recorded at which a sample of the plasticizer containing plasticwill 1 twist 200 in a 5-second period. The test sampl is 2.5 0 x 0. 25. x 0.040 inches in dimensionandhas mounting holes centered 2 inches apart. ,Any deviation in thicknes of thesample from the standard0,040 inch is corrected to thestandard thickness 1 according .to Figure 9 of the article cby; i:-

number. The estericut R. F. Clash, Jr. and R. M. Ber

clashcandzBerg. The final vvalue; Tn. for the '1 temperaturecof :fiex in degreescentigrade' :is ree corded. for eachof 1 the plasticizers noted in the.

tablefollowing;

The -"eificiency of my-novel 'plasticizing: agentm compared to that produced: from: di-isobutylene: wasnext determined, :both as to hardness and asto flexibility. This efliciency was calculated on'ie a percent basis as a measure of the effectiveness of my; plasticizer comparedto di-nonyl phthalate. derived from di-isobutylene' which was taken .as the-standard because of its acceptance in the; plasticizer art. The hardness andfiex tempera-- ture, Tr, of di-nonyl phthalate from di-isobutyb; ene was given a value of 100 per cent. To calculate the-efficiency of a plasticizer hav ing; for example, a flex temperature; Tr; 'of 17- C. for a sample containing 40 per cent plasticizer,-- the -concentration: of the standard di-nonyl phthalate derived from di-isobutylene to give that 20 flex'temperature is determined. Say itis foundto be :-37.7%.' The Tr-eificiency of the plasticizer tested is then 37.l 100/40 or 94 per cent; Hard ness-efli'ciency is calculated by the same method.

The 'characteristics -0f the orthophthalate'de rivatives of the two-'OXOnonyl alcohols-tested, namely, those produced from di-isobutyleneand" those-prepared froma copolymer of n-butene-l iority is inot. capable; .of rpredictionisinoe I both'i: alcohols are produced in the same..manner,thaver; the samemolecular-weight and differ only slight-,.

ly in structure.

The. .OXO nonyl alcohol of my.invention,

produced from n-butene-l andn-butene-2 copolymer, is superior'in all respects to OXO" nonyl alcohol from.-di-isobutylene except, possibly, as to relative economy. In that one in- ;stance--they' would probably be about equals- However, any "possible analysis of-the individual characteristics of the two -OXOialcoholsas set desirable plasticizing agents. 1

A sample. of 'the-di-nonyl phthalate plasticizer of my inventionwas compared-to di-octyl phthal-. ate. which is currently accepted as ,onepf the best, plasti-cizersin the plastics industry today. The volatility characteristics ascompared inrthe following table of results werefound to be par-: ticularly I interesting.

and n-butene-.2 according to my inventionare.v set-forth in the following table.-

TABLE I Orthophthalate plasticizers in polyvinyl chloride resin As may be readily observed from the above table,- the nonyl alcohol-of my invention, produc'ed from'a copolymer 'of 'n-butene-l and -n- V butene-Z by the OXOf process, is superior-in practically every respect-as to its'ability to form the most-desirable phthalate plasticizing'agent: 5

The OX0 nonyl alcohol of my invention produced-fromn-butene-l and n-butene-2 copolymer is shown in the-table above to have a volatility v loss of plasticizer of only 2.91%; This is less than one-thirdvof the loss sustained intheuse ohm-v 0X02 nonyl alcohol derived from di-isobutyl-- enen; In .1 both i hardness and; ,fiexefficiencymy OX0;nonylzalcoholzrates :at or above 105, com-1." pared::-to :the..;di-.isobutylene .fiOXO": alcohol; :as-:-: sisncdze'fficiency :of 100.: Such :a. decided LS11P6J2-11L75 The*OXO jnonyhalcohol of my invention is found to 'be superioreven' to the 2.-ethyl--hexyl= alcohol used in .the 'di-octyl 'phthalate -sincerit produces "a plasticizer :having; less tendency 'to". Reference ,to 'gTable II ShO'WS'that'thE loss "of -di-nonyl' 'phthalatet plasticizer of my invention was less than one= fourth the. loss of .the currently vvaccepted.di-ootyl... 'phthalate in similar. compositions. .This...sing1e".. characteristic. is of the..utmostv importance. since 1 it relatesdirectlyto theability. of the plastic. .to

volatilize "from the plastic;

withstand the effects. of aging .as previously pointed. out Furthermore, the OX0. f nonyl alcohol of my invention is far superior from the,

standpoint of economy since, it may be produced synthetically from petroleum refinery sources in far greater: quantities than corresponding types of alcohols from other sources;

In .view of the foregoingdisclosure, variations and modifications of the invention may become. apparent'to one. skilled in .the art. This invene.v tion; contemplates all such variations .and modi.-. fications. as coming.,.within.ithe scopeof the. .ap,--

pended claims.

I claim;

1. Di nonyl phthalate mixtures having a for: mula of the type wherein R.1.- and: are alkyl radicals containing-:- 18 carbonaatoms-sandrpossessing: chain structure found in copolymer mixtures of n-butene-l and n-butene-2. Number 2. Di-nonyl ortho-phthalate mixtures having 1.815 378 a formula of the type 1 993:736 5 2,015,077 II 2,015,088 C-OCHzR1 1 1 40 2,327,066 2,464,916 2,486,693 2,517,351 wherein R1 and R: are alkyl radicals containing 8 carbon atoms and possessing chain structure found in copolymer mixtures of n-butene-l and Number n-butene-2. 15 873,391

JOHN T. RUTHERFORD.

REFERENCES CITED 10 UNITED STATES PATENTS Name Date Schaack July 21, 1931 Graves Mar. 12, 1935 Lawson Sept. 24, 1935 Reid Sept. 24, 1935 Deansly Nov. 28, 1939 Rollen Aug. 7, 1943 Adams Mar. 22, 1949 Spijker Nov. 1, 1949 Reid- Aug. 1, 1950 FOREIGN PATENTS Country Date France July 7, 1942 OTHER REFERENCES Technical Oil Mission Microfilm Reel 14,

Frames 0000063'7-649; Reel 1, Frames 49-55; The following references are of record in the 20 Reel 14' Frames 6684373 (1942) Declassmed file 01 this patent:

Oct. 15, 1945. 

1. DI-NONYL PHTHALATE MIXTURS HAVING A FORMULA OF THE TYPE 